BuddyPress.org

@jamieea – you might want to check this one out:

http://www.dnxpert.com/2010/06/11/mark-blog-post-as-favorite-in-buddypress/

For it to work, you’ll need to have control over the themes being used for the member blogs (as it requires some code adding to single.php to create the favourite / unfavourite button.

Possible thoughts on enhancing this into something really special, borrowing ideas from del.icio.us: creating and sharing lists of favourites, annotating them with notes, and perhaps even allowing for links from outside the site to be added.